Polymerization induced Self-Assembly toward a new breakthrough for formulation of nanocarriers based on polysaccharide derivatives

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Physicochemical point of view in the evaluation of PR772 bacteriophage as a surrogate for human adenovirus

International audienceAmong pathogenic enteric viruses, human adenoviruses (HAdV) are characterized by numerous structural specificities. Indeed, the diameter of their icosahedral capsid is about 90 nm with projecting fibre of 30 nm at each vertex and their genome is a linear double stranded DNA of 35-36 kbp, whereas other pathogenic enteric viruses are RNA viruses with an icosahedral capsid of about 25 nm without fibre. But HAdV are also noteworthy by their high frequency from surface water to drinking water which is explained by their faecal excretion whatever the induced symptoms and by their resistance to environmental conditions and to some disinfection treatments such as UV and monochloramines. These particularities raise the question of the behaviour of HAdV in water. Because of their structural, genomic and replicative similarities, tectiviruses such as bacteriophages PRD1 and PR772 have been proposed as potential surrogate for HAdV. Thus, bacteriophage PR772 appeared as a promising surrogate in the understanding of HAdV type 2 inactivation by free chlorine. The aim of the present work was to compare the physicochemical characteristics of HAdV type 2 and bacteriophage PR772 in order to evaluate this phage as a surrogate to help understand the behaviour of HAdV in water networks. The isoelectric charge of both particles was monitored in different pH and ionic strength conditions. The values of the isoelectric point (pI) of HAdV type 2 and bacteriophage PR772 were between 3 and 4, meaning that these particles are negatively charged at neutral pH. Adhesion experiments on hydrophobic polystyrene beads were performed to compare the hydrophobicity of both particles. Hydrophobicity appeared as the main difference between HAdV type 2 and bacteriophage PR772. The role of hydrophobicity in the accumulation of viruses on surfaces might limit the use of bacteriophage PR772 as surrogate of HAdV in such experiments

Synthesis of dextran-based chain transfer agent for RAFT-mediated polymerization and glyco-nanoobjects formulation

International audienceGlycopolymers based on dextran are frequently prepared via ATRP, whereas the use of RAFT polymerization is strangely limited due to the difficult synthesis of Dextran-based macromolecular chain transfer agent (DexCTA). The aim of this work is to establish a controlled and reproducible methodology for its preparation. Direct esterification of the hydroxyl dextran functions is the most common method. Our study shows that this latter leads to a very low degree of functionalization. As alternative, we report a reproductible multistep strategy consisting of oxidation, amination, and amidation reactions. Various DexCTAs with tunable degree of substitution (respectively 0.025, 0.045, and 0.06) were successfully prepared. As proof of concept, one of the DexCTAs was involved in the photo-mediated RAFT polymerization of hydroxypropyl methacrylate in DMSO to prepare amphiphilic Dex-g-PHPMA glycopolymers, which can self-assemble in water into monodisperse spherical nano-objects. MTT assays revealed the biocompatibility of all dextran derivatives

Giant hybrid polymer/lipid vesicles (Chapter 27)

Intimate mixing of phospholipids and amphiphilic copolymers within same membrane of a giant vesicle requires particulate attention on both the molecular design and on the self-assembly process for synergetic benefits from both components.Cinétique de Translocation de Particules à travers de Bicouches Auto-Assemblée

Light-sensitive dextran-covered PNBA nanoparticles to continuously or discontinuously improve the drug release

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Synergistic Effects of Nanomedicine Targeting TNFR2 and DNA Demethylation Inhibitor—An Opportunity for Cancer Treatment

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A global database of soil nematode abundance and functional group composition [Data paper]

Measurement(s)Abundance center dot Nematoda center dot environmental factorTechnology Type(s)Elutriative Centrifugation center dot computational modeling techniqueFactor Type(s)geographic locationSample Characteristic - OrganismNematodaSample Characteristic - Environmentsoil environment center dot climateSample Characteristic - LocationEarth (planet) Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.11925843 As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns